The present invention relates generally to systems and methods for measuring strain in objects susceptible to conditions under which strain may develop within the object. In particular, the present invention relates to systems and methods for measuring strain in environments likely to produce strain in components of mechanical systems such as subsurface risers used in off shore hydrocarbon production.
Offshore oil and gas exploration and production are increasingly moving to deeper fields, more remote locations, and more environmentally sensitive waters. This trend is driving the need for longer risers and pipelines as well as more complex subsea processing (separation, compression, and pumping) equipment. The remoteness of these sites and heightened environmental concerns following the Macondo incident in the Gulf of Mexico have led to an industry-wide call for condition monitoring technology for all subsea assets.
Distributed fiber optic sensing technology has already proven to be highly valuable for in-well measurements during hydrocarbon production. A gap in the state-of-the-art is that no single platform exists which can monitor the many parameters that are needed to detect failure modes on subsea umbilicals, risers and flowlines (commonly referred to as SURF). Oil producers are calling for asset monitoring systems that can measure temperature, static and dynamic strain, acoustics, and chemistry, but the cost and complexity of deploying and maintaining multiple systems to achieve comprehensive monitoring of subsurface assets is a significant impediment. Hence, there is a clear need for a single cable solution with an integrated sensing and analytic system which possesses the high speed characteristics of an optical sensing system that is capable of reliably measuring strain, and other characteristics of the asset to be monitored such as temperature, pressure and acoustics.